How to decode base64 string and convert it into PDF/JPG and save it in storage

Question

I would like to decode a base64 string and turn it into a file (as PDF/JPG) and save it to device, how for example in (/storage/emulated/0/Download/file.pdf).

For encode a file I use this code:

File originalFile = new File("/mnt/sdcard/download/file.pdf");
    String encodedBase64 = null;
    try {
        FileInputStream fileInputStreamReader = new FileInputStream(originalFile);
        byte[] bytes = new byte[(int) originalFile.length()];
        fileInputStreamReader.read(bytes);
        encodedBase64=Base64.encodeToString(bytes,Base64.NO_WRAP);
        messaggio=encodedBase64.toString();
        //encodedBase64 = new String(Base64.encode(bytes));
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

Now, I would like to decode this base64 string and convert it into a file and save it on the device.

Answer 1

You can try this:

FileOutputStream fos = new FileOutputStream(filepath);
fos.write(Base64.decode(base64String, Base64.NO_WRAP));
fos.close();

Where:

• filepath: Path to the new file
• base64String: Your base64 string that you want to convert

Answer 2

Give READ_STORAGE and Write_STORAGE Permission in Manifest and dont forget for RunTime Permission.

 public static void storetoPdfandOpen(Context context, String base) {



    String root = Environment.getExternalStorageDirectory().toString();

    Log.d("ResponseEnv",root);

    File myDir = new File(root + "/WorkBox");
    if (!myDir.exists()) {
        myDir.mkdirs();
    }

    Random generator = new Random();
    int n = 10000;
    n = generator.nextInt(n);

    String fname = "Attachments-" + n + ".pdf";
    File file = new File(myDir, fname);
    if (file.exists())
        file.delete();
    try {

        FileOutputStream out = new FileOutputStream(file);
        byte[] pdfAsBytes = Base64.decode(base, 0);
        out.write(pdfAsBytes);
        out.flush();
        out.close();


    } catch (Exception e) {
        e.printStackTrace();
    }

    File dir = new File(Environment.getExternalStorageDirectory(), "WorkBox");
    File imgFile = new File(dir, fname);
    Intent sendIntent = new Intent(Intent.ACTION_VIEW);

    Uri uri;
    if (Build.VERSION.SDK_INT < 24) {
        uri = Uri.fromFile(file);
    } else {
        uri = Uri.parse("file://" + imgFile); // My work-around for new SDKs, causes ActivityNotFoundException in API 10.
    }

    sendIntent.setDataAndType(uri, "application/pdf");
    sendIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    sendIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
    context.startActivity(sendIntent);

}